A meteorite thin section from The Curchin Collection
What is NWA 10153?
Found in Northwest Africa in 2014, this meteorite is a Martian achondrite. It is classified as a nakhlite, which is a cumulate pyroxenite with large olivine phenocrysts. If this sounds like a terrestrial rock to you, then you are clued in to something special; cumulate pyroxenites form from magma, requiring a differentiated planetary body. Think core – mantle – crust.
How do we know it’s from Mars? A Martian origin for a meteorite is determined from a combination of isotope data, mineralogy, chemical composition, and trapped gas signatures, thanks to measurements made by the Viking Mars landers in 1976.
Under the Microscope
In cross-polarized light, clinopyroxenes and olivines put on a spectacular show of color. You can even see exsolution lamellae (parallel banding) in some of the elongated pyroxene grains. The white to tan orthopyroxene grains show iron-staining from surrounding iron-oxides.